Apparatus for controlling the transmission of vibrations



March 8, 1938.

R. W. BAlLY APPARATUS FOR CONTROLLING THE TRANSMISSION OF VIBRATIONS.

Jaw/W 2/73 M 2 Sheets-Sheet 1 Filed April 15, 1935 when x March 8, 1938. w 2,110,413 i APPARATUS FOR CONTROLLING THE TRANSMISSION OF VIBRATIONS Filed April 15, 1935 I 2 Shets-Sheet 2 Patented Mar. 8, 1938 UNITED STATES PATENT OFFICE APPARATUS FOR CONTROLLING THE TRANSMISSION OF VIBRATIONS Robert William Baily, Philadelphia, Pa.

Application April 15, 1935, Serial No. 16,411 I 13 Claims.

ing screeds and the like to forms or other sta-- tionary objects on which the screeds are usually supported.

A further object is to provide a method and apparatus for controlling at least a portion of the Vibrations transmitted from a vibrating member to forms or rails, which retain or are embedded in r a material which becomes plastic when vibrated,

such forms or rails also determining the elevation of the vibrating'member. I

My method is intended primarily for use in association with devices for vibrating masses of concrete or the like, which are plastic, it ,being a can readily be adapted for use with different types of concrete vibrator devices, and for different purposes to which they are put, and which will be eifective'for producing the desired result of 'at least reducing the transmission of vibrations from the vibrating device to the forms l and causing a greater proportion of ener y used for vibration to be imparted to the vibrating member rather than wasted in attempting to vibrate the forms.

With these and other objects in view, my in:

vention consists in the construction, arrange ment and combination of the various parts of my apparatus and in the practice of my method, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of a vibrating strike-off screed, including apparatus for reducing the transmission of vibrations of the screed to a rigid structure as exemplifying my invention.

Figure 2 is a. vertical, sectional view on the line 22 of Figure 1.

Figure 3 is a vertical, sectional view on the.

line 3-3 of Figure 1. v

Figure 4 is an enlarged, sectional view on the line 4-4 of Figure 1, showing details of construction for reducing vibration.

Figure 5 is a view similar to the right-hand end of Figure 1, showing a modified construction in use on a slightly different type of form. Figure 6 is a sectional view on the line 6-6 of Figure 5. i Figure 7 is a front elevation of a slightly modified form of construction, showing a vibrating I screed with the accessories of Figure 1 omitted,

" and showing the use of the method in connection with a screed with one end placed on a concrete roadway slab.

Figure 8 is a front elevation of another modi- 15 fled form of the invention.

Figure 9 is .a vertical, sectional view on the line 99 of Figure 8.

Figure 10 is a view similar to Figure 8, showing still another modified form.

Figure 11 is a sectional view on .the line llll of Figure 10.-

Figure 12 shows another modified form, this figure being a vertical, sectional view somewhat similar to Figure 11.

- Figure 13 is a view similar to Figure 12, showing the .use of coil springs instead of elastic bands; and

Figure 14 is a diagrammatic plan view illustrating a means for advancing the vibrating de- 3 vice along the forms.

In my co-pending application, Serial No. 428,747, I show a screed adapted to be moved over a plastic roadway material for striking off the top surface thereof and vibrating the mate- 3 rial.

In my Patent Number 2,018,294, issued October 22, 1935, methods are disclosed for damping the transmission of vibrations from a vibrating member to its supporting member, to handles mounted on said member and to prime movers utilized for actuating vibratory mechanisms, which are mounted on said member.

In the operation of such vibratory devices along rigid structures, such as steel girders, steel railway and ,car tracks, I have found that such a large proportion .of the available vibratory venergy is absorbed by the rigid structure that there remains an insufficient proportion thereof to properly treat the-plastic material, which it is desired to vibrate and thus compact and solidify.

Also in the operation of such devices in the construction of roadways in which the plastic material-is usually confined between the side forms, whichin turn rest upon an earthen suba The engine 36 is mounted on a platform 46, which grade of more or less stability, I have found that in some cases the side forms are displaced and moved from their desired positions due to the amount of vibration transmitted to them from the vibratory member which rests upon them. Even where the side forms may be sufliciently well supported to resist any tendency of the vibratory member to move or displace them, I have found that in some cases it is desirable to reduce the amount of vibratory energy, which is absorbed by the side forms and to impart a larger proportion of the available vibratory energy to the plastic material.

In other cases, I have found it necessary to eliminate as totally as possible the transmission of vibrations to the forms and have found it advisable in some cases to impart a reasonable amount of vibration to the forms in order to spade or puddle" intensively the plastic material in contact with the forms and to be able to control and regulate the amount of vibration transmitted to the forms. I

In still other cases, where one end of the vibrating screed rests upon a recently completed body of set material, it is desirable to eliminate in so far, as it may be possible to do so, the transmission of vibrations to such material, as there is a tendency to fracture it.

To attain these desirable results, I have conceived the present invention, which I will now describe.

In Figure 1, I have shown the apparatus being used in connection with car tracks l6 between which plastic material or concrete l2 has been placed. I also show side forms l4 and ties l6 in connection with this figure, the concrete I2 also being placed between the rails l6 and the forms l4. .The numeral It! indicates a vibrating strike-0B screed, which is formed of a plank or the like, so that it can be bowed for crowning dles 26, whereby the screed may be moved by workmen along the rails It or otherwise manipulated.\

Means is provided for vibrating this screed I6, this being shown in Figure 1, as a rotating shaft 36, having its ends journaled in. housings 32. Within the housings and secured to the shaft 36 ,are out-of-balance weights 34, this arrangement being similar to that shown in my Patent No.- 1,876,271. v

For rotating the shaft 30, I illustrate an engine 36 connected by a belt 38 with the shaft 30.

in turn is mounted on a crowning board 42.

The platform 46 is mounted-on the crowning board 42, preferably by-bolts 44 with elastic blocks or washers 46 interposed between the brackets 48 and washers 50, as shown inmy co-pending application, Serial No; 576,727. The brackets 48 are secured to the crowning board 42 by bolts 52. The crowning board 42 is mounted on the screed l8 by elastic strut members 54, one at each end of the board, and a third elastic strut member 66. The member 66 is adjustably mounted relative to the center of the board 42 by means of a plate 66 secured by a bolt 66 to the crowning board, and bolts 62 provided with adjustable lock nuts 64, engaging the top and bottom of the central portion of the strut 66, as shown in Figure 2.

The means for eliminating the transmission of vibrations from the screed member l6 to the rails l0 consist of elastic blocks 66 arranged in transverse grooves 66 of the screed I6. These blocks are in position above the rails Ill and are shod with metal plates 16 held in position by bolts 12 (see Figure 4) V Instead of the elements 66 and 10, metal leaf springs I4 can be used as in Figures 5 and 6, if desired, or other equivalent elastic means may be devised.

In Figure 5, I have shown the elastic means resting on a side form 16, such as used at the side of a concrete pavement slab Ho, and resting on a sub-grade 16.

In other instances, the vibration transmission eliminators 16 might be mounted on a special screed l6a as shown in Figure 7, having the end beyond one of the elements 16 cut off as indicated at the right-hand end of the figure This end is then adapted for travel on a slab I 2b of set concrete, the slab I2c being still plastic, and to I which the vibrations of the screed Illa are to be applied.

When the apparatus is in operation, the out-ofbalance weights 34 upon being rotated will induce vibrations in the screed l8, the directions of motion having both vertical and horizontal components lying in planes parallel to the forward direction of travel of the screed. Any plastic material, such as l2d collected in front of the wall 22 will receive the benefit of the horizontal components of the vibrations while the material l2 below the screed will receive the benefit of the vertical components.

If the member I6 were rigidly supported by the rails III the amount of vibration transmitted to the material l2, would be very small, but since the elastic members 66 are compressible, they will permit the member II to vibrate freely in a vertical direction and in directions other than vertical in the amplitude of the motion induced by the vibrator weights 34.

The elastic members 66 during this operation will alternately be compressed and then'allowed to expand, the lower face of the screed I! being maintained at the desired average elevation.

The elevation of the lower face of the screed may be regulated with respect to the upper surface of the rails I 6 or other support, such as 16,

in Figure 5, by tightening the bolts 16, which will depress the screed, or by loosening the bolts, which will elevate it relative to the rails.

'The curvature of the screed II, of course, can be adjusted as desired by raising or lowering the central strut member 56, by manipulating the lock nuts 64 in an obvious manner, the screed, however, being shown without curvaturein Figure 1.

The strut members 54 and 66 as has been stated are elastic, being made of spring steel or the like. Accordi gly they prevent the'transmission of a destructive amount of vibration from the vibrating screed II! to the crowning board 42, thus aiding in increasing the efficiency of the vibration transmission from the source of power of the engine 36 to the screed l8.

In Figures 8 and 9, I show a. means for controlling the amount of vibration transmitted from the vibrating screed to the side forms I6. The crowning board 42 in this case issupported on the forms, rather than the screed being supported on the forms, and then the crowning board supbolts 82 and elastic blocks 84 with brackets 86 on the crowning board. Elastic arms 88 are pivoted at 90 to the plate 80 and supporting rollers 92.

- opening I in the upper block 84 so as notto interfere with the action of the blocks.

In Figures and 11, I show modified forms of the arms 88 indicated by the reference numerals 8811. These are elastic but are not adjustable.

Another method of providing supports ior the vibrating member is shown in Figure 12. The

screed is indicated at I0b and does not extend over the side forms 16, but is then supported therefrom by a rigid yoke 88b through the medium of elastic'bands I02 and I04.

In Figure 13, springs M211 and I04a are illustrated instead.

The elastic supports such as 88 in Figure 9, while sufliciently stiff to support the screed I8 are also'sufliciently elastic to permit the screed to vibrate in vertical and horizontal directions without transmitting appreciable vibratory motion to the side forms I6. Accordingly the major portion of the useful vibratory-energy is transmitted to the screed only, and from the screed to the plastic material thereunder. The degree of transmission of vibrations to the side forms can be readily controlled by adjusting the crank 9H. If this crank is adjusted so that the nuts 96 approach each other, then the rollers 92 swing outwardly and upwardly from the screed I8, al-

\lowing itto move downwardly, and when the I nuts are moved -away from each other, the screed .is moved upwardly relative to the form 16.

In this manner, the transmission of vibrations to the forms I6- can be increased or decreased as desired.

The rollers 92 permit the apparatus to be moved about on the side forms in any horizontal direction. The loops I02 and I04 of Figure 12 can be of any desirable material of elastic nature. The loops I02 dampen vertical transmission of vibrations, while the loops I04 dampen horizontal transmission of vibrations to the supporting yokes 881).

In Figure 14, I show the screed I8 only without the apparatus associated with .it for vibrating it and preventing the transmission of these vibrations to the side forms 16. This figure is to illustrate one way in which the screed can be advanced along the side forms. A cable I06 has one end anchored to a stake I08 or a projection of the side form if desired, and extends around pulleys 0 on the screed, the other end being wound on a drum or winch II2.

The platform I I4 for the winch can be anchored as by stakes H6, and with this arrangement, when the cableis wound on the drum, the screed will be advanced toward the drum.

It is obvious from the foregoing that my method for damping and controlling the transmission of vibrations may be readily modified, the essential characteristic of the invention being in so supporting the screed relative to the side forms that it will be maintained at the desired elevation with the major portion of the available vibrating energy being absorbed by the screed and in turn by the concrete thereunder, with but a minimum of the vibrations tending to be absorbed by theside forms. Various modifications as illustrated on the drawings and other changes may be made without departing from their scope.

I claim as my invention: 1. An apparatus for striking off at a predeterthe real spirit and purpose of my invention, and

it is intended to cover by my claims any modified forms of structure or use of mechanical equivalents, which may be reasonably included withi mined contour and compacting a material which becomes plastic when vibrated, comprising a vibrating strike-off member for propulsion across said material. spaced forms for containing. said material, said vibrating strike-off .member having spaced portions resting on said forms to determine the elevation ofthe struck-off surface and means for damping the transmission of vibrations from said vibrating strike-01f member to said forms comprising elastic means interposed between each of said portions of said Vibrating strike-01f member and said forms, said elastic means being secured to said strike-oi? member as apart thereof.

2. A device for compacting a material which becomes plastic when subjected to vibration, rigid means for supporting said device and containing said material, said device including a vibratory member, the elevation of saidvibratory member being determined by said rigid means, said vibratory member being in contact with said material, and means for damping the transmission of vibrations from said vibratory member to said rigid means, comprising elastic means attached to the vibratory member as a part thereof and movable relative to the rigid means, said elastic means assuming a position of interposition, during operation, between the rigid means and the vibratory member.

3. A device for compacting material which becomes plastic when subjected to vibration, rigid means for supporting said device and containing said material, said device including a vibratory member, the elevation of said vibratory member being determined by said rigid means, said vibratory member being in contact with said material, means for damping the transmission of vibrations from said vibratory member to said rigid means, comprising elastic means attached to'said vibratory member as a part thereof and interposed between said rlgid means and said vibratory member, and means for propelling said device across said material 4. A device for compacting a material which becomes plastic when subjected to vibration, supporting members which contain part of said material, said device including avibratory member flat-wise in contact with said material, a crowning board mounted edgewise relative to said vibratory member, the elevation of said vibratory wibratory member to the forms.

vibrations, comprising a vibratory member, elastic means carried thereby as a part thereof and interposed between said apparatus and said supporting member for damping the transmission of ,vibrations from 'the vibratory member to the A '7. In an apparatus for striking of! and vibratinga material which becomes plastic when subjected to vibration and within structures'which contain it, the combination of a vibratory member, means for damping the transmission of vibrations therefrom to said structures, said last means being carried as a part of said vibratory member with contact means for supporting said vibratory member relative to said structures, which contact means are movable relative to said structures, said means for damping the transmis-- sion of vibrations comprising elastic connections between said contact means and said vibratory member, whereby the vibratory member, contact means and elastic connections form a unitary structure.

8. In an apparatus for striking 0i! and vibrating a material which becomes plastic when subjected to vibration and within structures which contain it, the combination of a vibratory member, -means for damping ,the transmission oi vibrations therefrom to said structures, such means being attached to said vibratory member as-a part thereof withimeans for determining.

the elevation of said vibratory member with relation to the elevation of said structures-and including angularly arranged supporting legs pivoted to said apparatus, screw threaded crank rod and nut means to change the angles or inclinatlon thereof, and means for propelling saidvibratory member across said material.

9. In an apparatus for vibrating a material which becomes plastic when vibrated .and which is contained within containing structures therefor, a vibratory member in contact with said material, the elevation thereof being determined by said structures, elastic means .to dampen the transmission of vibrations from said apparatus to said structures, sai'd elastic means being attached to said vibratory member as a part thereof, and means for adjusting the vertical contour of the vibratory member including an edgewise mounted crowning board and a variable length connection between the center thereof and the center of said vibratory member.-

10. In an apparatus for vibrating a material which becomes plastic when vibrated and within structures which contain it, a vibrating member in contact with said material and supported by said structures, the elevation of said member being determined by said structures, elastic means attached to said vibrating member as a part thereof and engaging said structures to damp the transmission 0! vertical vibrations from said member to said structures, means for propelling said apparatus across said material, means for adjusting the vertical contour oi! said vibrating membenand means for adjusting the elevation of said vibrating member in relation to said structures.

. 11. Anapparatus for vibrating a material which becomes plastic when vibrated and within structures which contain it, comprising a vibrating member in contact with said material and supported by said structures, the elevation of said member being determined by said structure,

elastic means attached to said vibrating member as a part thereof and engaging said structures to damp the transmission of vibrations from said apparatus to said structures, and means for adjusting the elevation of said vibrating member in relation to said structures, including a crowning board mounted edgewise relative to said vibrating member and a threaded rod and nut means of connection between the centers 01' said crowning board and vibrating member.

12. An apparatus for vibrating a material which becomes plastic when vibrated, said apparatus including a vibrating member in contact with said material, the elevation of said member being determined by. structures associated with 

